A plurality of different types of lamps for use in a vehicle headlight exists on the market today. Both incandescent halogen lamps and electrical discharge lamps comprise a light emitting element within a sealed transparent vessel.
DE 10 2008 022 144 A1 describes a halogen lamp for use in a vehicle headlight. In an example, the lamp is a H7 lamp with electrical power of 55 W at 13.2 V. A transparent lamp vessel with a cap at one end and an opaque covering at the other end comprises a cylindrical section around an axially arranged filament. A section surrounding the cylindrical section in ring-like manner is provided with an interference filter for reflecting infrared light to achieve a higher efficiency. The width of the filtering section corresponds to the length of the filament of 4-6.5 mm. The interference filter does not fully extend around the filament, but is comprised of ring segments separated by non-coated portions.
U.S. Pat. No. 4,987,343A discloses a combined glare and heat shield for vehicle headlamp applications. Such composite heat shield member is configured and located inside the headlamp assembly with particular respect to the light source so as to avoid shadowing by this lamp component in the projected light beam pattern.